Photon flashes white then blinks blue

[ScruffR]

You are in luck, just yesterday CLI 1.24.0 was released and this has the particle device doctor command implemented for exactly that

Particle Tools Changelog

Aug 29th 2017: particle device doctor The CLI release 1.24.0 adds a new device doctor command that resets many settings on a device to bring it back to health. Update the CLI with npm install -g particle-cli Run particle device doctor with a device connected over USB and follow the prompts. The CLI documentation lists all the settings that the Doctor resets. A a day keeps the Device Doctor away!